How and where to use guide
VELUX Twin and Combination Flashings 78x118cm EKW MK06 S0222
Suitable applications and installation locations
This flashing is intended for use with VELUX skylights in pitched timber roof constructions. It is appropriate for new build installations where you are fitting a VELUX skylight kit, and equally suitable for retrofit situations where you are replacing an existing skylight or upgrading its flashing. The flashing works with softwood and engineered timber roof members graded F16, F24, and F36. Ensure your skylight dimensions do not exceed 78cm × 118cm, as this is the maximum size the flashing accommodates. The combination design provides enhanced protection in exposed locations or where wind-driven rain is a concern.
- New VELUX skylight installations as part of a complete kit
- Retrofit and replacement work on existing skylights
- Pitched timber roofs with F16, F24, or F36 grade timber
- Skylights up to 78cm × 118cm in size
- Locations exposed to wind-driven rain
Installation and on-site fitting
The twin and combination design allows for flexible adjustment during installation. Position the flashing around the skylight frame, ensuring it sits flush against the roof structure and timber members. The PVC material can be carefully adjusted on site to accommodate minor variations in roof pitch or timber dimensions. Secure the flashing according to VELUX installation guidance, ensuring all edges are properly sealed and fastened. Check that the flashing overlaps roof covering materials correctly to direct water away from the skylight frame and into the roof drainage system. Work methodically around all four sides of the skylight to maintain an even, weather-tight seal.
- Position flashing around skylight frame before securing
- Adjust on site as needed to suit roof pitch and timber variations
- Ensure proper overlap with roof covering materials
- Secure all edges according to VELUX installation instructions
- Verify weather-tight seal around entire perimeter
Maintenance and durability
The PVC material is durable and requires minimal maintenance. Periodically inspect the flashing to ensure it remains securely fastened and that the seal around the skylight frame has not deteriorated. Clear any debris, moss, or lichen from the flashing surface to maintain water drainage and prevent pooling. Check that fasteners have not loosened due to thermal movement or weathering. If the flashing becomes damaged or the seal is compromised, plan for replacement to prevent water ingress into the roof structure.
- Inspect flashing annually for secure fastening and seal integrity
- Clear debris and organic growth to maintain drainage
- Monitor for signs of water ingress around the skylight
- Replace if damage or seal failure is detected
Limitations and important considerations
This flashing is designed specifically for VELUX skylights and timber roof construction. It is not suitable for skylights larger than 78cm × 118cm or for use with timber grades below F16. Do not use on flat roofs or non-timber roof structures without confirming compatibility. The flashing provides weather protection when correctly installed, but its effectiveness depends on proper sealing of all joints and edges. Always follow VELUX installation guidance and local building regulations for your region. If your roof timber grade or skylight dimensions fall outside the specified range, consult VELUX technical support or your installer before proceeding.
- Maximum skylight size 78cm × 118cm
- Timber grades F16, F24, F36 only
- Not suitable for flat roofs or non-timber structures
- Effectiveness depends on correct installation and sealing
- Refer to VELUX guidance and local building regulations